Plug-on electromagnetic relay with an external pocket



L. O. WOODS PLUG-ON ELECTROMAGNETIC RELAY WITH AN EXTERNAL POCKET Filed March 1, 1965 2 Sheets-Sheet 1 3,25%?Zfi75 z Sheets-Sheet 2 Nov. 22, 1% L... o. WOODS PLUG-ON ELECTROMAGNETIC RELAY WITH AN EXTERNAL POCKET Filed March 1, 1965 I ma /2/ for; {we 0.. Mods,

United States Patent 3,287,675 PLUG-0N ELECTROMAGNETIC RELAY WITH AN EXTERNAL POCKET Lee 0. Woods, Morrison, Ill., assignor to General Electric Company, a corporation of New York Filed Mar. 1, 1965, Ser. No. 436,240 8 Claims. (Cl. 335-202) This invention relates to plug-on electromagnetic relays and more particularly to plug-on electromagnetic relays having an open terminal-receiving pocket and lead holding means associated therewith.

In the past it has been a common practice to assemble all of the plug-on terminals in plug-on electromagnetic relays at the factory where the relays were assembled. The relay was then ready to be plugged onto the electrical apparatus when it was received by the customer. The customer usually made such electrical connections to the relay as were necessary by joining leads to other terminals provided in the relay by welding, soldering, brazing or some other similar method. If the customer desired to make additional electrical connections to the electrical apparatus to which the relay was connected, he made these other connections in separate operations. Thus, for extmple, a customer purchasing a relay might connect one end of the main winding and one end of the start winding of an electric motor to one input line from a power source through the relay by plugging the relay into the motor circuit. It was then necessary to connect the other ends of the main and start windings to the other input line in an entirely independent manufacturing step. It is desirable that this other input line be connected to the relay when it is plugged in. Preferably, the relay should supply not only the connecting vehicle but the strain relief and positioning for this additional connection.

It is, therefore, an object of my invention to provide an improved plug-on electromagnetic relay to which auxiliary terminals may be assembled without the use of sup plementary mounting hardware.

A further object of my invention is to provide a plugon electromagnetic relay to which a plug-on terminal may be quickly added to the relay assembly.

Still another object of this invention is to provide a plug-on electromagnetic relay with a novel female terminal receiving pocket and lead holding means for assembling a female terminal on a plug-on relay and securing its lead to the housing of the relay.

A still further object of this invention is to provide an improved plug-on relay having permanently mounted plug-on terminals and provision for the later addition of plug-on terminals.

By. way of illustration, in accordance with one form of my invention, I have provided an improved plug-on electromagnetic relay having a coil bobbin with two female plug-on terminals built into the relay at one end of the bobbin. A pocket is provided at this end of the bobbin for the assembly of an additional terminal in the relay after completion of the factory assembly of the relay. A catch means is provided on the relay to assure the firm attachment of the lead extending from the additional terminal in position on the relay. The attachment of the lead in position on the relay prevents the terminal from becoming disengaged from the pocket, provides strain relief for the lead and securely relates the lead to the relay so that it will not interfere with other surrounding apparatus.

As a further aspect of one form of my invention, I have provided a pocket at one end of the coil bobbin that opens through an outer wall of the relay housing. This pocket has an overhanging lip which is provided 3,287,675 Patented Nov. 22, 1966 by the outer wall of the relay housing. A buttress wall is provided in the pocket at its end opposite the lip. The additional orauxiliary terminal is inserted into the pocket with its plug-on end under the lip and a portion of its other end buttressed against the buttress wall. To prevent the terminal from either rising up out of the pocket or being pushed rearwardly in the pocket when the relay is plugged onto an electrical apparatus, a lead admitting slot is provided at the back of the pocket adjacent the buttress wall so that the lead from the auxiliary terminal can be pulled down into the relays housing to assure the firm and level positioning of the terminal in the relay.

As a further aspect of one form of my invention, I have provided a slot in an outer wall of the housing into which the lead wire from the auxiliary terminal may be secured. This slot has a restricted mouth so that the insulation on the lead must be compressed to force the lead into the slot. Thus, when the lead is in the slot, it is held there by the resiliency of the insulation which expands after compression to prevent the lead from coming back out of the slot. The lead extends from the terminus of the slot in a downward direction out of the way of surrounding apparatus with which the relay may be associated.

Further aspects of the invention will become apparent from the more detailed description of the invention. It will be understood that the specification concludes with the claims which particularly point out and distinctly claim the subject matter which I regard as my invention. The invention, however, both as to organization and method of operation, together with further objects and advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings in which:

FIGURE 1 is a front view of an electromagnetic relay embodying my invention in one form thereof;

FIGURE 2 is a rear view of the electromagnetic relay of FIGURE 1;

FIGURE 3 is a right side view of the electromagnetic relay of FIGURE 1 showing in broken lines my novel pocket with the auxiliary terminal inserted therein and in phantom lines the auxiliary terminal partially inserted in the pocket;

FIGURE 4 is a plan view of the electromagnetic relay of FIGURE 1 with the forward end and inner side edge of the terminal shown in dotted lines under the cover;

FIGURE 5 is a top view of the electromagnetic relay of FIGURE 4 with the cover removed and turned over to show its inside configuration;

FIGURE 6 is a sectional view taken on line 66 of FIGURE 1;

FIGURE 7 is a sectional view taken on 'line 77 of FIGURE 1;

FIGURE 8 is a partial isometric view of the electromagnetic relay of FIGURE 1 with the cover partially broken away to show the terminal receiving pocket with the terminal shown in phantom lines partially inserted in the pocket;

FIGURE 9 is a partial isometric view similar to FIG- URE 8 showing the terminal in full lines seated in the pocket with its lead secured in the lead catch means or slot;

FIGURE 10 is a side view of one of the terminals shown in FIGURE 5;

FIGURE 10a is a front end view of the terminal of FIGURE 10; and

FIGURE 11 is a wiring diagram showing the relay of FIGURE 1 utilized with an electric motor.

Referring now to FIGURES 1, 2 and 5 and the wiring diagram of FIGURE 11, the relay 20 can be seen to have a terminal 21 to which an input lead 22 from a power source is connected. The end 23 of the relay coil 24 is connected to terminal 21 by welding. The other end 25 of the coil 24 is connected to a female plug-on terminal 26. The relay switch 27 is connected to terminal 21 and to another terminal 30. Terminal 30 is connected by lead 31 to a female plug-on terminal 32. An auxiliary female plug-on terminal 33 which is connected to the other input lead 34 may be assembled to the relay 20 after its completion and shipment from the factory.

The relay 20 plugs onto a terminal board (not shown) which is electrically connected to an electric motor 35 having a main winding 36 and a start winding 37. The particular arrangement used in this case has male pins (not shown) projecting from the terminal board and mating with the female terminals in the relay. Of course, it would be possible to provide male pins in the relay and a female terminal board.

When the relay 20 is plugged onto the motor terminal board, relay terminal 26 is connected to one end of the main mot-or winding 36, relay terminal 32 is connected to one end of the start winding 37 and relay terminal 33 is connected to a common connection with the other ends of both the main motor winding 36 and the start winding 37. This may be seen from the diagram of FIGURE 11.

Referring now in particular to FIGURES l and 2, it may be seen that the electromagnetic relay 20 has a housing 40 which includes a bobbin 41 and a cover member 42. The coil 24 is wound on the bobbin 41. The bobbin 41 has a platform 43 (FIGURE at one of its ends. The platform 43 has a dividing wall 44 thereon. Two recessed seats 45 and 46 are formed in the platform on each side of the dividing wall 44 and a terminal seat 47 is provided on top of the dividing Wall. As may be seen in FIGURE 1, the arrangement of these three seats provides a good electrical separation of the relays plug-in terminals within a short linear space.

The cover 42 has portions which overlie the terminal seats 46 and 47 to secure terminals 26 and 32 permanently in position with their leads 31 and 25. Slots 50 and 51 guide the leads 3-1 and 25 from their respective terminals to the exterior of the relay housing 40. These slots 50 and 51 are closed from the rear where they pass through platform 43 by the rear wall of the cover member.

Looking now at FIGURE 4, the electromagnetic relay may be seen to have a front 52, a rear 53, a top 54 and two sides, a right side 55 and a left side 56. The bottom 57 of the relay is indicated in FIGURE 3. The sides of the cover and of the bobbin, of course, correspond to the sides of the electromagnetic relay. In other words, the front Wall 60 of the cover faces in the same direction as the front of the relay as may be seen in FIGURE 1. This cover also has a rear wall 61 (FIGURE 2), a right side Wall 62, a left side wall 63, a bottom surface or wall 64 and a top wall 65. The platform 43 of the bobbin 41 also has corresponding walls; a front wall 66 (FIGURE 5), a rear wall 67, a right side 70, a left side 71, a top wall 72 and a bottom wall 73 (FIGURE 7). Of course, these walls are really merged in many cases. For example, the top wall 72 and the bottom wall 73 of the platform 43 are really a single structural wall having two faces or surfaces facing in opposite directions.

Looking now at FIGURES and 10a, a female plugon terminal may be seen. This terminal is made from a resilient electrically conductive metal sheet that has a substantially planar portion 74, with two arms 75 and 76 bent around toward one another to form a female terminal. The planar portion 74 of the terminal extends rearwardly from the arms and it has an outer extremity 77 crimped to the lead. Two tangs 80 and 81 extend from the terminal portion 74. The rear edges 82 of the arms and the edges 83 and 84 of the V end of portion 74 serve as buttress edges. The front edge 85 of the terminal faces in the opposite direction from the direction in which buttress edges 82, 83 and 84 face.

Referring .to FIGURES 5, 6 and 7, the manner in which terminals 26 and 32 are mounted in the housing 40 of the relay 20 will be explained. Terminal 32 is exactly like the terminal shown in FIGURES l0 and 10a, and the recessed seat 46 into which terminal 32 is secured is exactly like the recessed seat 45 into which terminal 33 fits and the same numbers apply to both. Recess 45 may be seen in FIGURES 5, 8 and 9 to have a front wall 86, a bottom wall 88, and a rear but-tress wall 87 with two buttress shoulders 90 and 91. The buttress Wall has a recess 92 formed in it to allow extra clearance should the male terminal pass all the way through the female terminal when the relay is plugged into the motor circuit. A slot 93 leads from the recess 45 to join the recess 45 with the lead admitting slot 94 which is formed in the cover 42 (FIGURE 4). Recess 46 has only one continuous lead admitting slot 95 with a portion 96 in the top wall of the bobbin platform 43 and another portion 97 in the rear Wall of the bobbin platform (FIGURE 7).

Looking once again at FIGURE 5 it can be seen that the cover has a recess 100 and a recess 101 formed therein to engage over the tangs 80 and 81, respectively, (FIGURE 10) when cover 42 is secured in position on the bobbin with terminal 32 in position on the platform 43. Thus, when terminal 32 is placed in the position shown in FIGURE 5 on the platform 43 with its lead 31 positioned in slot 95 (FIGURE 7) and the cover is secured over the terminal, the terminal will be held permanently in secure position. The planar portion 74 of terminal 32 is engaged from above by the bottom wall of the cover with the tangs 80 and 81 engaged in the rcesses 100 and 101. The front edge 85 of the terminal is engaged against the front wall 86 of the recess, the buttress edges 82, 83 and 84 of the terminal are engaged against the buttress wall 87 and the arms 75 and 76 are engaged against the bottom wall 88. The crimped connection 77 and the lead 31 are engaged in slot 95 with the bottom wall of the cover over them.

Terminal 26 is secured in the housing 40 in much the same manner as terminal 32 except terminal 26 is mounted upside down. Thus, the cover 42 has a recess 102 formed in it and the seat 47 on the divider wall 44 has a tang receiving recess 103 formed in it. The tang 81 of terminal 26 is bent flush with planar portion 74 and the outer crimped portion 77 of the terminal is bent so that it registers with groove 104 as shown in FIGURE 6. The recess 102 in the cover 42 has a front Wall 105 and a rear buttress wall 106 with two buttress shoulders 107 and 110. The buttress wall 106 has a recess 111 formed in it to allow extra clearance for the male terminal. Slot 112 and other portions of the bottom wall 64 of the cover 42 cooperate with groove 104 and slot 51 to form an interrupted lead admitting or guiding slot. When the terminal 26 is placed on the seat 47 with tang 80 engaged in recess 103, outer portion 77 positioned in groove 104 and the lead positioned in slot 51, the cover 42 may be secured in position on the bobbin 41 to secure the terminal in position thereby trapping the terminal under the covers bottom wall 64 between the front wall 105 and the buttress wall 106.

Terminal 33 is exactly like the terminal shown in FIGURES l0 and 10a. Terminal 33 fits into a pocket 113 which opens through the outer top wall 54 of the relay 20 as shown in FIGURE 4. The pocket 113 opens to recess seat 45 which is like recess seat 46. Recessed seat 45 was described above when seat 46 was discussed. The pocket 113 has a lip 114 which extends over the front portion of the recess 45. The slot 93 extends from the recess 45 and is continuous with the lead admitting slot 94. The lead admitting or guiding slot 94 has two portions, a top wall portion 115 and a rear wall portion 116 (FIGURE 4). The slot 116 in the rear wall is horse shoe shaped, looking at the bottom wall of the cover 42' in FIGURE 5. Slot 116 has two lips 117 and 120 at its entrance from the rear of the relay 20 which provide a restricted slot entrance. The slot 116 terminates at the bottom wall 64 of the cover member 42.

To mount the auxiliary terminal 33 on the relay 20, it is only necessary to grasp the lead 34 in one hand and insert the front edge 85 of the terminal into pocket 113 at an angle as shown in FIGURES 3 and 8. The front edge 85 is then guided under lip 114 and lowered into the position shown in FIGURES 3 and 9. The lead 34 is held relatively taunt where it connects to the terminal 33 and lowered until it is bent and forced into le-ad catch slot 116. The insulation on the lead 34 is compressed when the lead is forced between lips 117 and 120 of slot 116. Once the lead 34 has snapped into slot 116, the insulation returns to its uncompressed position and the lead is held in the slot and directed downwardly from the bottom wall of the cover as shown in FIGURE 3 so that it will not interfere with surrounding apparatus when the relay is plugged into a circuit. The tight securing of the lead 34in bent position in slot 116 also holds the terminal 33 down in the pocket and prevents the terminal from falling out of the pocket or being easily dislodged from the pocket when a male terminal is pushed into it. The lip 114 and the buttress wall 87 also play important roles in preventing the terminal 33 from being dislodged from the pocket by holding it securely from above and from the rear.

It will :be understood that once the terminal is secured in the pocket and the lead 34 snapped into slot 116, the terminal is held from its front by the engagement of the front edge 85 of the terminal against the buttress edge 86 of the seat 45 (FIGURES l0 and 8). The terminal is held from its rear by the buttress wall 87 (FIGURE 9). The terminal 33 is held down by the lip 114 and by the engagement of lead 34 in slot 94 and the terminal is held against movement downwardly or to either side by the engagement of the arms 75 and 76 on the curved bottom wall 88 of the recess seat 45 and by slot 94 which includes slot 93 (FIGURES 4 and 8).

Looking once again at FIGURES 1 and 6, the front wall 60 of the cover member 42 may be seen to have three apertures 121, 122, 123 through it opening to the front edges of the terminals 32, 26, 33, respectively. These apertures permit the entrance of male terminals into electrical and mechanical engagement with the female terminals to connect the relay 20 into the motor circuit. The front wall 60 also extends over the entire front of the coil 24 and, therefore, the front wall would serve to insulate the coil both electrically and thermally from the front. The rear cover wall 61 is cut away to allow air to circulate about the coil.

While in accordance with the Patent Statutes I have described what at present is considered to be the preferred embodiment of my invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from my invention, and I, therefore, aim in the following claims to cover all such equivalent variations as fall within the true spirit and scope of this invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An electromagnetic plug-on relay for use with electrical apparatus, said relay having a housing, at least one terminal mounting pocket in said housing, said pocket opening from a first outer wall of said housing, a lip overlying a portion of said pocket, a buttress wall raised above the lower surface of said pocket, 2. lead guiding slot extending from said buttress wall and opening to a second wall of said housing, said housing being formed with an integral lead catch means for holding a lead extending from a terminal mounted in the terminal mounting pocket in position on said housing, said lead catch means cooperating with said pocket, said lip, and said buttress wall to retain a terminal and its lead in secure position on said housing.

2. An electromagnetic plug-on relay for use with electric motors of the type having main windings and start windings; said relay having a bobbin with a platform at its top end; said platform having a raised divider wall projecting from its top surface; said platform having a front wall facing in the direction in which it plugs on and a rear wall facing in the opposite direction; said platform having a terminal seat on its top surface on each side of said divider wall; said divider wall having a terminal seat on its top surface; said rear wall having two slots therein passing through said platform and connected respectively with two of said terminal seats to form two lead guides extending from the seats to the lower face of the platform; two female terminals with leads connected thereto; said two female terminals engaged on said terminal seats with their leads engaged in the lead guides; a cover member positioned over said platform and divider wall; said cover extending over said terminal seats and lead guides to secure said terminals and leads in position; said cover having a top wall, a front wall, a rear wall and a bottom wall; an aperture through said cover to said other lead seat; said aperture opening from above, behind the front edge of said seat to provide a lip extending over the front edge of said seat, said cover having a lead catch slot terminating in a position to direct a lead secured therein downwardly, said aperture being dimensioned to receive a third female terminal in a manner requiring the terminal to be inserted from above with its mouth down and its lead up; the third female terminal being inserted from above and then slipped under the lip; as the third terminal is seated in the aperture its lead can be bent into position in the catch slot which secures the terminal in position, tensions the connection between the terminal and lead and directs the lead downwardly; and said cover member having a front face with three apertures through it opening to the respective female terminals.

3. The electromagnetic plug-on relay of claim 2 wherein the front face of the cover extends over the relay coil to shield the coil electrically and thermally, the rear face of the cover being open adjacent the coil to allow exposure to air circulation.

4. An electromagnetic plug-on relay for use with electric motors of the type having main windings and start windings; said relay having a bobbin with a platform at its top end; said platform having a raised divider wall projecting from its top surface; said plat-form having a front wall facing in the direction in which said relay plugs on and a rear wall facing in the opposite direction; said platform having a terminal recess in its top surface on each side of said divider wall; said recess opening through generally aligned slots to the front and rear walls of said platform; said divider wall having a seat on its top surface and a groove extending down one of its edges to the base of said divider wall; said rear wall having two slots passing through said platform; one of said rear wall slots aligned with one of the slots extending to one of the recesses to form one lead guide and the other rear wall slot aligned with said groove to form another lead guide; two female terminals with leads connected thereto; one of said terminals engaged in said terminal recess with its lead engaged in said lead guide and the other terminal engaged on said terminal seat with its lead engaged in said other lead guide, a cover member positioned over said platform and divider wall; said cover extending over said terminal recesses, said terminal seat and said lead guides to secure said terminals and leads in position; said cover having a top wall, a front wall, a rear wall and a bottom wall; an aperture through said cover to said other recess in the platform; said aperture opening behind the front edge of said recess from above; said cover having a lead catch slot extending from its bottom wall across its rear Wall and to said aperture, said aperture being dimensioned to receive a third female terminal in a manner requiring the terminal to be inserted from above with its mouth down and its lead up, the third female terminal being inserted from above and then slipped under the cover toward 7 the front edge of the recess in the platform, as the third terminal is seated in the aperture its lead can be snapped into the catch slot to secure the terminal in position.

5. An electromagnetic plug-on relay for use with electrical apparatus, said relay having a housing, a first terminal mounting pocket in said housing, a first electrical terminal mounted in said first terminal mounting pocket, an opening through a first outer wall of said housing to said first terminal mounting pocket providing access to said first electrical terminal for electrical connection thereto, means for mounting a second electrical terminal in said housing including, a second terminal mounting pocket in said housing for receiving the second electrical terminal therein, an opening through said first outer wall of said housing to said second terminal mounting pocket providing access to the second electrical terminal for electrical connection thereto, a second outer wall of said housing having an enlarged opening overlying at least a portion of said second terminal mounting pocket and providing access to said second terminal mounting pocket from exteriorly of said housing to permit installation of the second electrical terminal into the second terminal mounting pocket of said housing.

6. The electromagnetic plug-on relay of claim 5 including a lip overlying a first end of said second terminal mounting pocket and a buttress wall raised above the lower surface of said second terminal mounting pocket at the end thereof opposite said first end, the second electrical terminal being securely retained within said second terminal mounting pocket by the opposed lip and buttress wall upon installation thereof through said enlarged opening.

7. The electromagnetic plug-0n relay of claim 6 having the second electrical terminal mounted in said second terminal mounting pocket with a first portion thereof underlying said lip and a second portion being exposed by said enlarged opening thereby permitting visual inspection of said second electrical terminal.

8. The electromagnetic plug-on relay of claim 5 wherein said second outer wall of said housing includes slot means extending between said enlarged opening and an opening in a third outer wall of said housing, said opening in said third outer wall having a restricted entrance to retain therein an electrical lead extending from said second electrical terminal.

References Cited by the Examiner UNITED STATES PATENTS 1,908,728 5/1933 Bollman 336192 2,682,038 6/1954 Iolnson 339-204 2,769,881 11/1956 Hailes 200104 X 2,888,662 5/1959 Hanrmell 339-217 2.907,847 10/1959 Grenier et al 200-468 X 3,058,091 10/1962 Henschen 339217 BERNARD A. GILHEANY, Primary Examiner.

J. BAKER, Assistant Examiner. 

1. AN ELECTROMAGNETIC PLUG-ON RELAY FOR USE WITH ELECTRICAL APPARATUS, SAID RELAY HAVING A HOUSING, AT LEAST ONE TERMINAL MOUNTING POCKET IN SAID HOUSING, SAID POCKET OPENING FROM A FIRST OUTER WALL OF SAID HOUSING, A LIP OVERLYING A PORTION OF SAID POCKET, A BUTTRESS WALL RAISED ABOVE THE LOWER SURFACE OF SAID POCKET, A LEAD GUIDING SLOT EXTENDING FROM SAID BUTTRESS WALL AND OPENING TO A SECOND WALL OF SAID HOUSING, SAID HOUSING BEING FORMED WITH AN INTEGRAL LEAD CATCH MEANS FOR HOLDING A LEAD EXTENDING FROM A TERMINAL MOUNTED IN THE TERMINAL MOUNTING POCKET IN POSITION ON SAID HOUSING, SAID LEAD CATCH MEANS COOPERATING WITH SAID POCKET, SAID LIP, AND SAID BUTTRESS WALL TO RETAIN A TERMINAL AND ITS LEAD IN SECURE POSITION ON SAID HOUSING. 